How Many Detection Methods Do Bearing Testing Machines Have? Fault Detection Method Analysis

Different structures, basic principles, and main applications of mechanical equipment result in distinct characteristics of common bearing faults. Based on on-site inspection practices and application scenarios, how can bearing testing machines identify abnormalities through fault analysis? Below is a summary of the detection methods of bearing testing machines.

Detection Methods of Bearing Testing Machines

1. Vibration Frequency Detection

Due to manufacturing variations, some newly installed bearings exhibit characteristic frequencies of specific components—typically the characteristic frequencies of the inner and outer rings—resulting in relatively high speed values. However, these amplitude values do not increase; in some cases, they gradually decrease with operation. Such conditions do not affect the normal use of the bearing, but this only applies to newly installed units. Leveraging the properties of high-frequency bearing vibrations—rapid attenuation and poor transmission—testing machines can accurately measure the speed and acceleration amplitude of each bearing. Faulty bearings show significantly greater amplitude values compared to normal ones, especially in acceleration amplitude, with differences ranging from several to dozens of times.

2. Temperature Detection

Elevated bearing temperatures are generally caused by bearing defects or lubrication issues. If the cause is a bearing defect, it typically indicates the mid-to-late stage of a fault. When analyzing temperature characteristics, the key focus is on temperature rise rather than just the absolute temperature value. Notably, sudden increases in temperature and high-frequency vibration may sometimes stem from lubrication problems rather than inherent bearing defects. To differentiate: Apply new lubricating grease and observe the vibration response. If vibration returns to normal afterward, the issue is lubrication-related; if vibration reverts to the previous high level within hours or more, a bearing defect is likely present.

3. Noise Detection

Bearing faults are usually accompanied by noise, and different faults produce distinct noise patterns—identifying which requires rich on-site experience. A sharp, single-tone noise is often caused by localized faults, which typically do not lead to temperature increases, allowing sufficient time to schedule maintenance. However, if the noise is accompanied by other irregular sounds, it indicates severe friction, often with a noticeable temperature rise, and the bearing must be replaced immediately.

Intermittent abnormal noise is generally caused by surface defects on rolling elements. As the rolling elements rotate, the defective surface may not align with the load-bearing area at all times, resulting in intermittent noise.

The above is a comprehensive introduction to the detection methods of bearing testing machines. Temperature, noise, and frequency are the three core indicators for diagnosing bearing faults. However, during the early, middle, and late stages of a fault, abnormal noise and frequency do not necessarily lead to temperature increases, nor does a temperature rise mean the bearing is irreparably damaged.